To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) Member Function - This option is correct. Constructors are member functions of a class that are used to initialize objects of that class.

Option B) Same name as Class name - This option is correct. Constructors have the same name as the class they belong to.

Option C) Default constructor initializes all non-initialized fields and variables to zero - This option is correct. If we do not provide a constructor for a class, the compiler automatically adds a default constructor that initializes all non-initialized fields and variables to their default values, which is zero for numeric types.

Option D) Compiler adds an empty constructor if we do not write our own constructor - This option is correct. If we do not provide any constructors for a class, the compiler adds a default constructor (which is an empty constructor with no parameters) to the class.

Therefore, all of the options A, B, C, and D are true about constructors.

The correct answer is A, B, C, and D. These options are correct because constructors are member functions, have the same name as the class, the default constructor initializes non-initialized fields to zero, and the compiler adds an empty constructor if we do not write our own constructor.

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• Wrong explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) The code on line 31 throws an exception - This option is incorrect. The finally block will only be executed if an exception is thrown or caught within the try block. In this case, if an exception is thrown on line 31, it will not be caught within the try block, so the finally block will not be executed.

Option B) The code on line 33 throws an exception - This option is correct. If an exception is thrown on line 33, it will be caught by the catch block on line 34. After the catch block is executed, the finally block on line 37 will be executed.

Option C) The code on line 35 throws an exception - This option is correct. If an exception is thrown on line 35, it will be caught by the catch block on line 34. After the catch block is executed, the finally block on line 37 will be executed.

Option D) The code on line 33 executes successfully - This option is correct. Even if the code on line 33 executes successfully without throwing an exception, the finally block on line 37 will still be executed. The finally block is always executed, regardless of whether an exception is thrown or not.

Therefore, the correct answer is options B, C, and D.

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• Wrong explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) Alpha a = x; - This option is incorrect because the object 'x' is of type Beta, which is a subclass of Alpha. Therefore, it can be assigned to a variable of type Alpha without any issue.

Option B) Foo f = (Alpha)x; - This option is incorrect because the object 'x' is of type Beta, which is a subclass of Alpha. The cast to Alpha is valid since Beta is a subclass of Alpha. Additionally, 'x' can be assigned to a variable of type Foo because Beta indirectly implements the Foo interface through its superclass Alpha.

Option C) Foo f = (Delta)x; - This option is correct because the object 'x' is of type Beta, and you are trying to cast it to Delta. Since Delta is not a superclass of Beta, this cast will result in a ClassCastException. It is not possible to cast an object to a type that is not in its inheritance hierarchy.

Option D) Beta b = (Beta)(Alpha)x; - This option is incorrect because the object 'x' is already of type Beta, so there is no need for the cast. The cast to Alpha is also unnecessary since Beta is a subclass of Alpha. Therefore, this code will not cause a ClassCastException.

The correct answer is Option C. This option will cause a java.lang.ClassCastException because you are trying to cast an object of type Beta to a type that is not in its inheritance hierarchy (Delta).

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• Wrong explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) Euro returns correct values - This option is correct. In the Euro class, the getCountry(String timeZone) method calls the super.getCountry() method, which is inherited from the Money class. Since the getCountry() method in the Money class does not take any arguments and simply returns the value of the country field, this method will return the correct value.

Option B) An exception is thrown at runtime - This option is not mentioned in the given code snippet. Therefore, it is incorrect.

Option C) Yen and Euro both return correct values - This option is incorrect. The Yen class overrides the getCountry() method and returns super.country. However, the super.country expression is incorrect. The country field is private in the Money class and cannot be accessed directly by the Yen class. Therefore, the Yen class will not return the correct value.

Option D) Compilation fails because of an error at line 25 - This option is correct. The Yen class attempts to access the country field of the Money class using super.country, but the country field is private and cannot be accessed from a subclass. This will result in a compilation error.

The correct answers are A and D.

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• Wrong explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) The time to determine whether a Person object is contained in a HashSet is constant and does NOT depend on the size of the map - This option is incorrect. The time to determine whether a Person object is contained in a HashSet is dependent on the size of the HashSet. In the worst case scenario, if all the elements in the HashSet have the same hash code (as in the given code where the hash code is always 420), the time complexity becomes O(n), where n is the number of elements in the HashSet.

Option B) Deleting a Person key from a HashMap will delete all map entries for all keys of type Person - This option is incorrect. Deleting a Person key from a HashMap will only delete the specific entry associated with that key. It will not delete entries for other keys of type Person.

Option C) Inserting a second Person object into a HashSet will cause the first Person object to be removed as a duplicate - This option is incorrect. HashSet does not allow duplicate entries. When inserting a second Person object into a HashSet, the first Person object will not be removed as a duplicate. The HashSet will simply not allow the second Person object to be added if it is a duplicate of an existing object.

Option D) The time to find the value from HashMap with a Person key depends on the size of the map - This option is correct. In a HashMap, the time to find the value associated with a specific Person key is dependent on the size of the map. The time complexity for finding an element in a HashMap is typically O(1) on average, but in the worst case scenario, it can be O(n), where n is the number of elements in the map.

The correct answer is D. The time to find the value from a HashMap with a Person key depends on the size of the map.

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• Wrong explanation

To access the DIAMETER member of the Geodetics class, we need to understand the different ways to access static members.

Option A) import com.sun.scjp.Geodetics; public class TerraCarta { public double halfway(){ return Geodetics.DIAMETER/2.0; } }

This option is correct because it imports the Geodetics class and accesses the DIAMETER member using the syntax Geodetics.DIAMETER.

Option B) import static com.sun.scjp.Geodetics; public class TerraCarta { public double halfway() { return DIAMETER/2.0; } }

This option is incorrect because it tries to import the Geodetics class using the static keyword, but it does not specify which member of the class to import. Therefore, the line return DIAMETER/2.0; will cause a compilation error because DIAMETER is not recognized.

Option C) import static com.sun.scjp.Geodetics. *; public class TerraCarta { public double halfway() { return DIAMETER/2.0; } }

This option is correct because it imports all the static members of the Geodetics class using the * wildcard. Therefore, the line return DIAMETER/2.0; will correctly access the DIAMETER member.

Option D) package com.sun.scjp; public class TerraCarta { public double halfway() { return DIAMETER/2.0; } }

This option is incorrect because it does not import the Geodetics class, so the line return DIAMETER/2.0; will cause a compilation error because DIAMETER is not recognized.

Therefore, the correct answers are Option A and Option C.

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• Wrong explanation

To answer this question, you need to understand how to access an enum type that is defined inside a class.

In the given code, the enum Direction is defined inside the class Nav. The Sprite class is trying to access this enum.

Let's go through each option to understand why it is correct or incorrect:

Option A) Direction d = NORTH; - This option is incorrect because NORTH is not directly accessible in the Sprite class. To access the NORTH value, you need to specify the enum type Direction.

Option B) Nav.Direction d = NORTH; - This option is incorrect because NORTH is not directly accessible in the Sprite class. Additionally, the correct way to access the enum type Direction is by using Nav.Direction to specify the fully qualified name.

Option C) Direction d = Direction.NORTH; - This option is incorrect because Direction.NORTH is not directly accessible in the Sprite class. To access the NORTH value, you need to specify the enum type Direction.

Option D) Nav.Direction d = Nav.Direction.NORTH; - This option is correct because it specifies the fully qualified name Nav.Direction to access the enum type Direction and the NORTH value. This allows the Sprite class to compile successfully.

The correct answer is option D. This option is correct because it correctly accesses the enum type Direction using the fully qualified name Nav.Direction and initializes the variable d with the value Nav.Direction.NORTH.

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• Wrong explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) Foo { public int bar() { return 1; } } This option is incorrect because it is missing the keyword "new" before the Foo interface. The Foo interface needs to be instantiated with a concrete implementation.

Option B) new Foo { public int bar() { return 1; } } This option is incorrect because it is missing a set of parentheses after "new Foo". When instantiating an interface with an anonymous class, the parentheses are required.

Option C) newFoo() { public int bar(){return 1; } } This option is correct because it correctly instantiates the Foo interface with an anonymous class and provides an implementation for the "bar()" method.

Option D) new class Foo { public int bar() { return 1; } } This option is incorrect because it is attempting to create a new class named "Foo" instead of instantiating the Foo interface. The keyword "class" is not needed in this context.

The correct answer is Option C. This option is correct because it properly instantiates the Foo interface with an anonymous class and provides an implementation for the "bar()" method.

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• Wrong explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) The code compiles and the output is 2 - This option is incorrect. If lines 16, 17, and 18 were removed, the class A would not implement the bar() method from the Foo interface. Therefore, the code would not compile, and there would be no output.

Option B) If lines 16, 17, and 18 were removed, the code would compile and - This option is correct. If lines 16, 17, and 18 were removed, the class A would not implement the bar() method from the Foo interface. However, since the fubar() method accepts a parameter of type Foo, it can still accept an instance of any class that implements the Foo interface, including the nested class A defined in the testFoo() method. Therefore, the code would compile.

Option C) If lines 24, 25, and 26 were removed, the code would compile and the output would be 1 - This option is correct. If lines 24, 25, and 26 were removed, the nested class A defined in the testFoo() method would not be used. Instead, the class A defined outside the testFoo() method would be used, which implements the bar() method and returns 2. Therefore, the code would compile, and the output would be 2.

Option D) If lines 24, 25, and 26 were removed, compilation would fail - This option is incorrect. If lines 24, 25, and 26 were removed, the nested class A defined in the testFoo() method would not be used. However, the code would still compile and execute using the class A defined outside the testFoo() method.

Therefore, the correct answer is:

A) The code compiles and the output is 2 B) If lines 16, 17, and 18 were removed, the code would compile and C) If lines 24, 25, and 26 were removed, the code would compile and the output would be 1

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• Wrong explanation